In physical systems, individual properties change continuously and macroscopic systems show emergent changes in their phases. Here we show that social systems may exhibit parallel properties. To the best of our knowledge, our work provides the first experimental evidence of the existence of multiple phases in human movements, a hypothesis posited theoretically two decades ago [1]}. Future research is required to experimentally manipulate control parameters such as temperature that are hypothesized to control these phase transitions.
Inspired by these empirical observations, we proposed a social interactive model that captures the nature of human orientational interactions at different distances. Our model not only reproduces the observed social phases but also captures several physical quantities including radial distribution and angular correlation functions, in qualitative agreement with empirical measurements. The results shed light on the role of social interactions in human movement, with potential implementations in fields including behavioral science [2]}, biological science and epidemiology [3]}.
